From personal observation, usually it’s the bicyclist behaving badly, not the car driver. Not that the car driver is particularly innocent, but it’s usually the bicyclist breaking one or more traffic laws to begin with.
Even after I came to a screeching halt, they STILL tried to cross in front of me and in the face of another oncoming car.
I am wondering what an 81 year old is doing on a bicycle riding on the highway anyway.